Conventionally, polymer or inorganic particles have been manufacture by the batch process, because it is impossible to continuously synthesize monodisperse polymer particles or inorganic particles of a desired particle size, a desired degree of cross-linking and a desired structure.
For example, U.S. Pat. No. 5,863,996 discloses a batch process for manufacturing polymer particles.
In order to obtain a desired product, the batch process for manufacturing polymer particles includes feeding monomers or reactants containing monomers into a batch reactor to perform a polymerization reaction and separately performing a plurality of processes, such as cooling down, removing and washing the polymer.
U.S. Pat. No. 5,411,602 discloses another method for manufacturing particles that includes spraying minute solder particles into an inert gas flow with a sprayer and capturing solidified balls. U.S. Pat. No. 4,744,821 describes a method of forming minute particles and passing them through oil and water layers. U.S. Pat. No. 4,302,166 discloses an apparatus for forming minute particles that involves dropping particles into an aqueous solution of nonionic surfactant. U.S. Pat. No. 4,787,935 describes a method for producing powder by cooling down a fluid in a stream of vortex to solidify into minute particles.
However, the conventional apparatuses or methods for manufacturing particles are not only inappropriate to produce particles having a wide particle size distribution, like inorganic particles such as silica particles other than polymer particles but also problematic in that the particles thus produced are of a non-uniform size, an uneven surface, and a low purity.
In an example to prepare inorganic particles, Korean Patent Publication No. 10-2012-0092428 discloses an apparatus for manufacturing silica particles used as a silicon source for large-scaled production of SiC with high purity that is in the spotlight as a material having low density, high melting point, high strength at high temperature, high thermal resistance and high oxidation resistance for use purpose in all kinds of heat-resistant structural members, industrial furnace members, next-generation heat exchangers, gas turbines, and piston engines.
However, the conventional apparatus for manufacturing silica particles that uses batch reactors is unsuitable for use in the continuous process, produces particles with low purity and non-uniform particle size and hardly forms the particles in globular shape.